The process for preparing the antibiotic steffimycin, and the description of its various biological properties, are disclosed in U.S. Pat. No. 3,309,273. The antibiotic at that time was known as steffisburgensimycin.
The process for preparing steffimycin B and its characterization are disclosed in U.S. Pat. No. 3,794,721.
The structures of steffimycin and steffimycin B can be shown as follows: ##STR1##